In electric staplers used in post-processing devices, a staple guide portion for guiding a staple to be struck out is provided on a staple cartridge, in which staples are received (e.g., see Japanese Patent Application Publication No. 2004-209561). As staple guide portions, a staple cartridge has been proposed, in which a staple leg support member is provided to oppose a guide member provided on a front end of the staple cartridge and referred to as a face plate or the like, and staple legs of a staple struck out from the staple cartridge is pressed against the guide member by the staple leg guide member.
For staplers on which such a staple cartridge is attached, a technique has been proposed, in which a clamping portion for clamping sheets of paper is formed by a part of a case constituting the exterior of the staple cartridge (e.g., see Japanese Patent Application Publication No. 2006-26860). The case of the staple cartridge is typically configured of a resin material. In such a conventional staple cartridge, the staple leg support member configured of a metal material is exposed on the clamping portion formed by the case configured of a resin material.
In the conventional staplers, the staple leg support portion is exposed on the clamping portion formed by the case of the staple cartridge. Since the case of the staple cartridge and the staple leg support member are separate components, a groove, a step and the like formed at a boundary between the clamping portion and the staple leg support member are exposed on the surface of the clamping portion.
Therefore, there is a possibility that during an operation of inserting sheets of paper into the paper clamping portion, the sheets of paper are caught on the groove, the step and the like and thus a poor insertion of the sheets of paper is occurred. Also, in a configuration in which the staple leg support member is not provided, the staple legs of the staple cannot be sufficiently supported during an operation of forcing the staple legs to penetrate the sheets of paper. Therefore, there is a possibility that buckling of the staple legs is occurred.